Tapered sleeve

ABSTRACT

The present disclosure describes methods of making a sleeve comprising a conical frustum having first and second end profiles and a lumen there through for covering and constraining an expandable device, and apparatuses, systems, and assemblies comprising an expandable device and a sleeve having a frustoconical shape when the expandable device is at least partially expanded. The present disclosure further describes methods for deploying an expandable device in a patient comprising releasing a releasable seam disposed on a sleeve and everting the sleeve while retracting it from the expandable device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.14/183,303, filed Feb. 18, 2014, which claims priority to U.S.Provisional Application No. 61/772,984, filed Mar. 5, 2013, both ofwhich are herein incorporated by reference in their entireties.

FIELD

The present disclosure relates generally to the remote orientation anddeployment of implantable medical devices and, more particularly, toimplantable expandable devices surrounded by constraining sleeves.

BACKGROUND

Medical devices are frequently used to treat the anatomy of patients.Such devices can be permanently or semi-permanently implanted in theanatomy to provide treatment to the patient. Frequently, these devices,including stents, grafts, stent-grafts, filters, valves, occluders,markers, mapping devices, therapeutic agent delivery devices,prostheses, pumps, bandages, and other endoluminal and implantabledevices, are inserted into the body at an insertion point and deliveredto a treatment site using a catheter. Common types of expandable devicesinclude stents and stent-grafts.

Expandable devices such as stents or stent-grafts are used in a varietyof places in the human body to repair aneurysms and to support variousanatomical lumens, such as blood vessels, respiratory ducts,gastrointestinal ducts, and the like. Expandable devices can have areduced diameter when in a collapsed configuration, and can be designedto spontaneously dilate (i.e., elastically recover), or beballoon-expanded, from their collapse configuration, through one or moreintermediate configurations, up to a maximum functional configuration.Expandable devices can be constrained in the collapsed configurationwith a sleeve to facilitate transport to the treatment site.

The endoluminal delivery and deployment of expandable devices posepotential issues. First, the expandable device itself must be radiallycompacted to a suitable delivery configuration to allow insertion intothe vasculature, constrained and mounted onto a delivery device such asa catheter. Subsequently, the constraint must be removed in order toallow the expandable device to expand or be expanded to its functionalconfiguration and achieve the desired therapeutic outcome. A variety ofways of constraining and deploying an expandable device are known in theart. For example, an expandable device can be constrained by one or moresleeves with deployment comprising the removal of the one or moresleeves.

As such, there is an ongoing need to improve the endoluminal deliveryand deployment of expandable devices such as stents and stent-grafts.New devices, assemblies and methods of deployment that can improve theuse of sleeve-constrained expandable implants would be useful anddesirable.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure. The drawings incorporated in andconstituting a part of this specification illustrate embodiments of thedisclosure, and together with the description, serve to explain theprinciples of the disclosure, wherein like numerals denote like elementsand wherein:

FIG. 1A illustrates a partial cutaway side view of an embodiment of anassembly comprising an expandable device constrained in a collapsedconfiguration in accordance with the present disclosure;

FIG. 1B illustrates side views of embodiments of an expanded device anda sleeve in accordance with the present disclosure;

FIG. 2 illustrates a perspective view of an embodiment of a sleeve inaccordance with the present disclosure;

FIG. 3 illustrates an unwrapped sheet of material usable to form anembodiment of a sleeve in accordance with the present disclosure; and

FIGS. 4A, 4B and 4C illustrate side views of an embodiment of anexpandable device being deployed in accordance with the presentdisclosure.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Persons skilled in the art will readily appreciate that various aspectsof the present disclosure can be realized by any number of methods andsystems configured to perform the intended functions. Stateddifferently, other methods and systems can be incorporated herein toperform the intended functions. It should also be noted that theaccompanying drawing figures referred to herein are not all drawn toscale, but can be exaggerated to illustrate various aspects of thepresent disclosure, and in that regard, the drawing figures should notbe construed as limiting.

With that said, and as will be described in more detail herein, variousembodiments of the present disclosure generally comprise sleevescomprising a conical frustum usable for constraining expandable devices,assemblies comprising an expandable device and a sleeve having afrustoconical shape when the expandable device is in an intermediateconfiguration, and methods for deploying an expandable device in apatient comprising the eversion and retraction of a frustoconical-shapedsleeve from an expandable device.

As used herein, “proximal” indicates a position closer to the heart ofthe patient, or to a portion of a device that, when implanted, is closerto the heart of the patient than another portion of the device. “Distal”indicates a position farther from the heart of the patient, or to aportion of a device that, when implanted, is farther from the heart ofthe patient than another portion of the device. Implanted devices havingtubular or rod-like shape comprise a distal end, a distal portion, amedial portion, a proximal portion, and a proximal end moving from theend farthest from the heart to the end closest to the heart.

With further regard to the terms proximal and distal, and because thepresent disclosure is not limited to peripheral and/or centralapproaches, this disclosure should not be narrowly construed withrespect to these terms. Rather, the devices and method described hereincan be altered and/or adjusted relative to the anatomy of a patient.

An “expandable device” can include, for example, any device suitable fordelivery to the treatment site at a delivery diameter and capable ofdilation from the diameter of the delivery profile, through a range ofintermediary diameters, up to a maximal, pre-determined functionaldiameter. Such expandable devices can include endoluminal prosthesessuch as stents, grafts and stent-grafts.

As used herein, an “assembly” can include, for example, a combination ofan expandable device, such as a stent or stent-graft, a delivery device,such as a catheter, and other related accessories, components, anddevices.

As used herein, a “sleeve” can include any enclosure constraining anexpandable device. In various embodiments, a sleeve can comprise a sheetof material wrapped around an expandable device in a collapsed,intermediate, or treatment configuration.

As used herein, the term “constrain” means: (i) to limit expansion,occurring either through self-expansion or assisted expansion, of thediameter of an expandable implant; or (ii) to cover or surround, but nototherwise restrain, an expandable implant such as for storage orbiocompatibility reasons and/or to provide protection to the expandableimplant and/or the vasculature.

As used herein, “deployment” refers to the actuation of a device at atreatment site, such as for example, the release and/or removal of asleeve from a self-expanding device to allow the device to expand. Thedeployment process can be in stages, such as for example, a first stagecomprising the release of a sleeve to a configuration suitable toconstrain the expandable device only to an intermediate configuration,and a second stage comprising the removal of the sleeve altogether fromthe device.

As used herein, “conical frustum” means a portion of a hollow cone thatlies between two parallel planes cutting it, or in other words, atruncated cone. As used herein, “frustoconical” means having the shapeof a frustum of a cone.

As used herein, “eversion” means a process whereby a structure is turnedinside-out. As used herein, “evert” means to turn something inside-out.An “everted” structure is a structure that has been everted, (i.e.,turned inside-out).

Sleeves in accordance with the present disclosure can comprise a conicalfrustum that constrains an expandable device in an intermediateconfiguration. In various embodiments, a sleeve can be any other shapesuitable for constraining an expandable device in a collapsedconfiguration. In various embodiments, a sleeve can change shape from afirst shape that constrains an expandable device in a collapsedconfiguration, to a second shape that constrains the expandable deviceto an intermediate or fully expanded configuration. In variousembodiments, a sleeve can be entirely removed from an expandable deviceby everting the sleeve while retracting it from the expandable device.

With reference now to FIG. 1A, an assembly 100 in accordance with thepresent disclosure is illustrated in a partial cutaway side view.Assembly 100 comprises an expandable device 104 (viewable within thepartial cutaway for discussion purposes), and at least one sleeve 106.As illustrated in FIG. 1A, the sleeve 106 circumferentially surroundsthe expandable device 104, and constrains it in a collapsedconfiguration in which the diameter is less than the diameter of anyintermediate configuration, which is less than the diameter of a fullyexpanded, treatment configuration. In various embodiments, the sleeve106 can constrain an expandable device 104 to any intermediate diameterbetween the fully expanded diameter and the fully collapsed diameter. Atleast one coupling member 130 can coordinate with rows of openingsdisposed on the sleeve 106 to secure the sleeve 106 around theexpandable device 104.

In various embodiments, the coupling member 130 can comprise a wovenfiber or a monofilament fiber. Any type of string, cord, thread, fiber,or wire capable of constraining a sleeve around an expandable device iswithin the scope of the present disclosure. For example, the couplingmember can comprise expanded polytetrafluoroethylene (ePTFE), ePTFEfiber such as (KORETEK®), sutures of polyethers such as polyethyleneterephthalate (DACRON® or MYLAR®) or polyacrylamides such as KEVLAR®.The coupling member 130 may comprise a metal wire made from nitinol,stainless steel, or gold.

In various embodiments, the assembly 100 can include a catheter 102having a distal end 108 and a proximal end 110. The expandable device104 can be constrained in a collapsed configuration by sleeve 106 andmounted near the proximal end 110 of the catheter 102. The assembly 100also has proximal and distal ends that correspond to those of thecatheter 102.

In various embodiments, expandable device 104 comprises a stent-graft.Stent-grafts are designed to expand from a collapsed delivery diameter,through a range of intermediary diameters, up to a maximum, oftenpre-determined functional diameter, and generally comprise one or morestents and one or more graft members disposed over and/or under thestent.

In various embodiments, the expandable device 104 can comprise a stent.A stent can include, for example, a plurality of stent rings, cut tubes,wound wires (or ribbons) or flat patterned sheets rolled into a tubularform. Stent rings can be operatively coupled to one another with a wire.Stent components can be formed from metallic, polymeric or naturalmaterials and can comprise conventional medical grade materials such asfor example nylon, polyacrylamide, polycarbonate, polyethylene,polyformaldehyde, polymethylmethacrylate, polypropylene,polytetrafluoroethylene, polytrifluorochlorethylene, polyvinylchloride,polyurethane, elastomeric organosilicon polymers; metals such as ironalloys, stainless steels, cobalt-chromium alloys, nitinol, and the like;and biologically derived materials such as bovine arteries/veins,pericardium and collagen. Stent components can also comprisebioresorbable organic materials such as poly(amino acids),poly(anhydrides), poly(caprolactones), poly(lactic/glycolic acid)polymers, poly(hydroxybutyrates) and poly(orthoesters).

In various embodiments, expandable device 104 can be self-expanding.Such devices dilate from a radially collapsed configuration to aradially expanded configuration when unconstrained.

In various embodiments, expandable device 104 can be balloon-expandablewith the assistance of a secondary device such as, for example, aballoon catheter or spring mechanism.

In various embodiments, the expandable device 104 can further compriseat least one graft member. The graft member can comprise, for example,expanded polytetrafluoroethylene (ePTFE), polyester, polyurethane,fluoropolymers, such as perfouorelastomers and the like,polytetrafluoroethylene, silicones, urethanes, ultra high molecularweight polyethylene, aramid fibers, and combinations thereof. Otherembodiments for graft material can include high strength polymer fiberssuch as ultra-high molecular weight polyethylene fibers (e.g., Spectra®,Dyneema Purity®, etc.) or aramid fibers (e.g., Technora®, etc.).

As illustrated in FIG. 1B, expandable device 104, unconstrained bysleeve 106, can comprise a radially expanded configuration suitable forimplant in the treatment area of a patient's vasculature. In theexpanded configuration, the diameter of expandable device 104 can beapproximately the same as the vessel to be repaired, or slightly largerthan the vessel to be treated to provide a traction fit within thevessel. Prior to expansion of the expandable device 104 to the expandedconfiguration engaged with the vasculature, sleeve 106 may haveconstrained the expandable device 104 in an intermediate configuration.In various embodiments, the sleeve 106 can comprise a first end profile,a second end profile and a lumen extending between the end profiles,wherein the first end profile and second end profile are different. Invarious embodiments, the end profiles can be planar, and parallel. Insome embodiments, planar end profiles need not be parallel. In variousembodiments, the sleeve 106 can be frustoconical, with opposing endportions having planar circular perimeters parallel to each other. Invarious embodiments, either or both circular end portions can benon-planar.

Referring now to FIG. 2, sleeve 106 comprises a conical frustum having afirst end profile 203 with first end profile perimeter 213, and a secondend profile 205 with second end profile perimeter 215. In variousembodiments, each of first end profile perimeter 213 and second endprofile perimeter 215 are substantially circular, though they may havenon-circular shapes in other embodiments. In various embodiments, firstend profile 203 and second end profile 205 can be substantially planarand parallel to each other. In various embodiments, the difference insize between the first end profile 203 and the second end profile 205can be about twice the wall thickness of the sleeve 106, or greater, asdiscussed below. In some embodiments, the difference in size need onlybe the difference required for the sleeve 106 to be everted.

Sleeve 106 further comprises a first seam 207 disposed between first endprofile 203 and second end profile 205, though in other embodiments,sleeve 106 can be formed without such a seam. For example, sleeve 106can be made by wrapping tape around a frustoconical mandrel andthermally bonding the windings into a sleeve, optionally leaving an endof the tape extending from the sleeve for attachment to one or more pullmembers (discussed below). In various other embodiments, sleeve 106 canbe made by an extrusion process, or by stretching a cylindrical sleeveover a frustoconical mandrel into a tapered, frustoconical shape. Sleeve106 can be formed from a sheet of material 250 wrapped into afrustoconical shape and joined along first seam 207. In variousembodiments, first seam 207 can be perpendicular to both first endprofile 203 and second end profile 205. By wrapping a sheet of material,sleeve 106 includes a lumen that extends through the conical frustum andconnects the first end profile 203 and the second end profile 205. Invarious embodiments, first seam 207 can be releasable (i.e., it can beopened) or permanent.

In various embodiments, a sheet of material 250 of any particularthickness can be wrapped to form a frustoconical sleeve 106, wherein thedifference in the diameter of second end profile 205 and the diameter ofthe first end profile 203 is equal to, or greater than, twice thethickness of the sheet of material 250.

In some embodiments, sleeve 106 further comprises a first row ofopenings 212 and a second row of openings 214 that can be coupledtogether into a releasable second seam with a coupling member (e.g.,coupling member 130 in FIG. 1A) to reduce the overall size of sleeve106, possibly change its shape, and constrain an expandable devicewithin sleeve 106 to a collapsed delivery configuration.

In various embodiments, sleeve 106 can comprise materials similar tothose used to form graft members. A sleeve can be made of any suitablematerial, including for example, a fluoropolymer such as ePTFE.Alternatively, or in combination with a fluoropolymer, the sleeve can beformed of biocompatible materials, such as polymers, which can includefillers such as metals, carbon fibers, Dacron, glass fibers or ceramics.Such polymers can include olefin polymers, polyethylene, polypropylene,polyvinyl chloride, polytetrafluoroethylene which is not expanded,fluorinated ethylene propylene copolymer, polyvinyl acetate,polystyrene, poly(ethylene terephthalate), naphthalene dicarboxylatederivatives, such as polyethylene naphthalate, polybutylene naphthalate,polytrimethylene naphthalate and trimethylenediol naphthalate,polyurethane, polyurea, silicone rubbers, polyamides, polycarbonates,polyaldehydes, natural rubbers, polyester copolymers, styrene-butadienecopolymers, polyethers, such as fully or partially halogenatedpolyethers, copolymers, and combinations thereof. Also, polyesters,including polyethylene terephthalates, polypropylenes, polyethylenes,polyurethanes, polyolefins, polyvinyls, polymethylacetates, polyamides,naphthalane dicarboxylene derivatives, and natural silk can be includedin the sleeve.

Referring now to FIG. 3, an unwrapped sheet of material 250 for forminga sleeve, such as for example sleeve 106, is illustrated. In variousembodiments, sheet of material 250 can comprise the minor portion of anannulus 360 having minor arc of radius a and major arc of radius (a+b).First straight end 307 and second straight end 327 can be broughttogether to form first seam 207 (FIG. 2). In this way, the sheet ofmaterial 250 can be wrapped around an expandable device to constrain theexpandable device in an intermediate configuration. In this way, thefirst seam 207 (FIG. 2), formed by joining the two opposite straightends of the minor portion of the annulus, can have length approximatelyequal to b.

With continued reference to FIG. 3, sheet of material 250 can furthercomprise a first row of openings 212 and a second row of openings 214.The rows of openings can be linear and parallel to each other. Invarious embodiments, the first row of openings 212 can begin at a pointwhere first straight end 307 meets the minor arced edge 317. Similarly,the second row of openings 214 can begin at a point where secondstraight end 327 meets the minor arced edge 317. Both rows of openingscan extend out to the major arced edge 337 of the annulus portion asillustrated. As discussed, first row of openings 212 and second row ofopenings 214 can be joined into a releasable second seam with a couplingmember threaded or woven through the openings. A coupling member can beof sufficient length to form a remote pull line used for tensioning anddeployment of an expandable device constrained by a sleeve. When anexpandable device is at the treatment site of the patient, the couplingmember can be disengaged from the sleeve from outside of the body of thepatient, which allows the sleeve to open along the releasable seam andthe expandable device to expand or be available for assisted expansion.

FIGS. 4A, 4B and 4C illustrate an embodiment of a method of deploying anexpandable device in a patient in accordance with the presentdisclosure. In various embodiments, deployment of an expandable devicecan comprise at least two stages. For example, a first stage cancomprise the opening of a releasable second seam on a sleeve, allowingan expandable device constrained therein to self-expand, or be availablefor expansion, from a collapsed delivery configuration to anintermediate configuration. In various embodiments, the tensioning andremoval of a coupling member from the sleeve can operate to open thereleasable second seam. The sleeve can comprise a conical frustum whenthe expandable device is in an intermediate configuration. For example,after tensioning and removal of a coupling member, the sleeve cancomprise a conical frustum having a smaller first end profile at thedistal end of the sleeve and a larger second end profile at the proximalend of the sleeve. In various embodiments, the sleeve, prior to theopening of the releasable second seam, can begin in a cylindrical shape,or in any other shape suitable to constrain the expandable device in acollapsed delivery configuration.

In various embodiments, the first stage of deployment can comprise therelease of a primary sleeve that coaxially surrounds both an innersecondary sleeve and an expandable device. In this way, release of theprimary sleeve allows the expandable device to self-expand, or to beavailable for expansion, to an intermediate configuration stillconstrained by a secondary sleeve comprising a conical frustum or othershape.

In various embodiments of a method for deploying an expandable device ina patient, a second stage can include retracting and removing a sleevefrom the expandable device through eversion. For example, afrustoconical-shaped sleeve can be everted and removed from anexpandable device by retracting the larger second end profile of thesleeve in a distal direction over the tapered body of the sleeve towardand over the smaller first end profile. In various embodiments, one ormore remote pull lines can be tethered to the larger end profile of thesleeve to assist in a controlled and even retraction of the sleeve. Forexample, several pull lines can be tethered symmetrically around thesecond end profile. In various embodiments, the tethered pull line orpull lines can be formed as an integral portion of the larger endprofile of the sleeve, such as through extension of a reinforcing fiberthat circumscribes the larger end profile. These and otherconfigurations for the larger end profile of the sleeve can helpmaintain strength and a low delivery profile for the sleeve.

By retraction of the larger end profile of the sleeve, the sleeve iseverted as the larger second end profile is pulled over and past thesmaller first end profile. By continued retraction, the sleeve iscompletely everted and removed from the expandable device, with thefirst smaller end profile of the sleeve departing from the distal end ofthe expandable device at the completion of the eversion process. As thesleeve is everted in this manner, the expandable device expands, orbecomes available for expansion, from an intermediate configuration to afully expanded treatment configuration. Optionally, once the sleeve iseverted and removed, any unexpanded portions of the expandable devicemay be optionally expanded.

With reference now to FIG. 4A, sleeve 106 comprising a conical frustumis everted and retracted from expandable device 104 by pulling thelarger second end profile perimeter 215 in the distal direction over thetapered body of sleeve 106 toward the smaller first end profileperimeter 213, as shown by the directional arrows. During the eversion,the larger second end profile perimeter 215 will circumferentiallysurround the tapered body of the sleeve as the larger second end profileperimeter 215 is retracted. With the expandable device in anintermediate configuration, rather than in a collapsed deliveryconfiguration, the radial force from the expandable device 104 on thesleeve 106 has less impact on the eversion process. In this way, asleeve comprising a conical frustum can be everted and pulled off anexpandable device by retraction in the distal direction.

Referring now to FIG. 4B, further retraction of the second end profileperimeter 215 over and beyond the first end profile perimeter 213 in adistal direction continues to evert the sleeve 106 to ultimately free itfrom the expandable device 104.

Referring now to FIG. 4C, continued retraction of the second end profileperimeter 215 in a distal direction ultimately frees the sleeve 106 fromthe expandable device 104. In this way, the sleeve 106 is turnedinside-out when fully separated from the expandable device 104.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present disclosurewithout departing from the spirit and scope of the disclosure. Thus, itis intended that the present disclosure cover the modifications andvariations of this disclosure provided they come within the scope of theappended claims and their equivalents.

Likewise, numerous characteristics and advantages have been set forth inthe preceding description, including various alternatives together withdetails of the structure and function of the devices and/or methods. Thedisclosure is intended as illustrative only and as such is not intendedto be exhaustive. It will be evident to those skilled in the art thatvarious modifications may be made, especially in matters of structure,materials, elements, components, shape, size and arrangement of partsincluding combinations within the principles of the disclosure, to thefull extent indicated by the broad, general meaning of the terms inwhich the appended claims are expressed. To the extent that thesevarious modifications do not depart from the spirit and scope of theappended claims, they are intended to be encompassed therein.

What is claimed is:
 1. A method of making a sleeve for covering amedical device, the method comprising: overlapping a portion of a firstsurface of a sheet of material with a portion of a second surface of thesheet of material such that the sheet of material is positioned aroundthe medical device to constrain the medical device in an intermediateconfiguration with a smaller diameter than an unconstrainedconfiguration and the sheet of material includes a first seam and formsa structure that has a first end and a second end, the structure havinga first profile wherein a diameter of the first end is different from adiameter of the second end; and forming a second seam by joining a firstportion of the first surface on a first side of the first seam with asecond portion of the first surface on a second side of the first seamthat is opposite the first side of the first seam such that thestructure adopts a second profile wherein the medical device isconstrained in a collapsed configuration with a smaller diameter thanthe intermediate configuration and the diameter of the second end in thesecond profile is smaller than the diameter of the second end in thefirst profile.
 2. The method of claim 1, wherein the second seam is areleasable seam.
 3. The method of claim 1, further comprising securingthe second seam with a removable coupling member.
 4. The method of claim1, wherein the first profile is a tapered profile.
 5. The method ofclaim 1, wherein the structure in the first profile is frustoconicallyshaped.
 6. The method of claim 1, wherein the structure in the secondprofile is cylindrically shaped.
 7. The method of claim 1, wherein thediameter of the first end in the second profile is smaller than thediameter of the first end in the first profile.
 8. The method of claim1, further comprising forming a first row of openings in the sheet ofmaterial and a second row of openings in the sheet of material.
 9. Themethod of claim 8, further comprising forming a first row of openings inthe sheet of material and a second row of openings in the sheet ofmaterial such that the first and second rows of openings are parallelwith one another prior to overlapping the first and second surfaces toform the first seam.
 10. The method of claim 8, further comprisingforming a first row of openings in the sheet of material and a secondrow of openings in the sheet of material such that the first and secondrows of openings are nonparallel in the first profile, and such that thefirst and second rows of openings are parallel in the second profile.11. The method of claim 8, wherein joining the first portion of thefirst surface on the first side of the first seam with the secondportion of the first surface on the second side of the first seamincludes joining together the first and second row of openings.
 12. Themethod of claim 8, wherein the first and second rows of openings extendbetween the first and second ends of the structure.
 13. The method ofclaim 1, wherein the sheet of material is annular shaped and defined bya first edge, a second edge, a third edge, and a fourth edge, whereinthe first edge is concentric with the second edge, and wherein third andfourth edges are nonparallel and extend between the first and secondedges.
 14. The method of claim 13, wherein the overlapped portion of thefirst surface is overlapped with the portion of the second surface suchthat the first edge forms an edge of the first end and such that thesecond edge forms an edge of the second end.
 15. The method of claim 1,wherein the biocompatible material is a fluoropolymer.
 16. The method ofclaim 15, wherein the fluoropolymer is expanded polytetrafluoroethylene.17. A method of making a sleeve for covering a medical device, themethod comprising: providing a sheet of biocompatible material; joininga first portion of the material with a second portion of the materialsuch that the sheet of biocompatible material is positioned around themedical device to constrain the medical device in an intermediateconfiguration with a smaller diameter than an unconstrainedconfiguration and forms a first seam and a structure having a taperedprofile; forming a second, releasable seam by joining a portion of thematerial on a first side of the first seam with a portion of thematerial on a second side of the first seam such that the structureadopts a cylindrical profile to constrain the medical device in acollapsed configuration with a smaller diameter than the intermediateconfiguration.
 18. The method of claim 17, wherein cylindrical profileis different from the tapered profile.
 19. The method of claim 17,wherein the biocompatible material is a fluoropolymer.
 20. The method ofclaim 19, wherein the fluoropolymer is expanded polytetrafluoroethylene.21. A method of making a sleeve for covering a medical device, themethod comprising: forming a first releasable seam of a tube of materialafter the tube of material is positioned around the medical device toconstrain the medical device in an intermediate configuration with asmaller diameter than an unconstrained configuration, the tube ofmaterial having a taper in diameter along a longitudinal length of thetube of material; and forming a second releasable seam with the tube ofmaterial by joining opposing portions of the tube of material such thatthe taper in diameter of the tube of material is reduced to constrainthe medical device in a collapsed configuration with a smaller diameterthan the intermediate configuration.
 22. The method of claim of claim21, wherein forming the second releasable seam includes reducing thetaper in diameter to no taper in diameter along the longitudinal lengthof the tube of material.
 23. The method of claim 21, wherein formingeach of the first and releasable second seams includes stitchingopposing portions of the material together.
 24. The method of claim 21,wherein prior to joining opposing portions of the tube of material suchthat the taper in diameter of the tube of material is reduced theopposing portions of the tube of material to be joined are non-parallelto one another and after joining the opposing portions together thejoined opposing portions are parallel with one another.